"When we got our first sale contract, our fax machine was broken," says Lukas Biewald, CEO and co-founder of Crowdflower, a labor-on-demand crowdsourcing company. "Not only that, but for the first year we were working from coffee shops, so when someone would ask our address, I'd joke, 'Er... we have multiple locations.'"

Those days are over for Biewald and his co-founder Christopher Van Pelt, who serves as CTO. The duo now works in a sunny, plant-filled, loft-like office in San Francisco's Mission District surrounded by two-dozen employees and an artist-in-residence. After inclusion in the TechCrunch 50 and an influx of $5 million in venture capital late last year, the company has grown three-fold in the past nine months.

Crowdflower matches an international online workforce with companies that need a large volume of simple work completed quickly. The cost to companies that use Crowdflower is based on the difficulty of tasks, the accuracy they require tasks to be done with, and a mark-up that varies depending on the complexity of finding quality workers, and assuring the quality of their work. By just filling out an online form, businesses, for a cost that's much lower than hiring a temp staff, or opening a phone bank, can access a global workforce to do projects that range from mundane to time-intensive.

More than 300,000 individual workers have helped complete 2,000 tasks via Crowdflower. A worker might only be paid pennies per task that takes a few seconds to complete, but those pennies add up quickly over hours. "When you total all the work, all the man-hours we're able to complete in, say, an hour, it's amazing," says Van Pelt.

The company uses formulas to control quality, such as training workers before they begin a task, checking samples of work, scoring the worker's historical accuracy, and gauging the level of agreement among workers on a given task. For example, workers might be asked to tag a pool of photos online. When workers' tasks overlap and they agree – say two workers describe the same image as "calico" and "cat" — both their credibility ratings rise.

The company's long-term goal? To change the way labor works, making it possible for anyone around the world to earn a little by doing a little. That acute ability to connect with workers online everywhere, anytime, also led Crowdflower into working toward social good. In the wake of the January earthquake in Haiti, an emergency SMS number was set up – 4636. Very quickly, the number was swamped with pleas for help. Crowdflower stepped in alongside Samasource, another crowdsourcing labor start-up, with technology that routed messages to volunteers in the U.S. Haitian diaspora who translated them and shared the content with the proper emergency workers. Today, Crowdflower also works with Samasource to bring digital jobs to refugee camps. "It's amazing how many people in the world we can touch in a single day," says Van Pelt.